MAIN/STANDBY 125 WATT RADIOBEACON TRANSMITTERS WITH CRCU and NDDS/T
(USER SUPPLIED ENCLOSURE/CABINET)
IS02007 (Page 9)
15 February 2002
INITIAL START-UP PROCEDURES
6.
The initial start-up procedures consist of an
individual functional test for the computer remote
control unit, the digital synthesizer and each
transmitter and then a check of main/standby
operation. It is recommended both transmitters and
the computer remote control unit be tested as a
standalone transmitter prior to checking the main/
standby functions.
(a)
Connect a precision 50-ohm dummy load which
is rated at a minimum of 250 watts and has
provision to accurately display the RF power
being applied to it, to the system's RF output
connector.
6.1 CRCU
CHECK:
Check the operation of
the computer remote control unit (CRCU) as detailed
in its instruction manual.
NOTE
The
CONTROL
switch of both transmitters must be set
to
REMOTE
for the CRCU to have on/off control of the
transmitters. When operational checks on the CRCU
are completed, set the
CONTROL
switch of both
transmitters to
LOCAL
.
6.2 NDDS/T
CHECK:
Check the operation
of the NDDS/T Dual Direct Digital Synthesizer as
detailed in its instruction manual.
6.3 CHECK OF TRANSMITTER 'A':
Complete a stand alone functional test of transmitter
'
A
' as follows:
(a)
Turn off or verify transmitter '
B
' has been turned
off. Set its
POWER
switch to
OFF
.
(b) Perform a complete functional test of transmitter
'
A
', including remote control operation, as
detailed in the ND500II technical instruction
manual.
(c)
On completion of tests, set the transmitter's
MOD
and
KEYING
switches to
ON
.
Ensure the carrier
level and modulation depth are set to the
intended levels.
6.4 CHECK OF TRANSMITTER 'B':
Complete a stand alone functional test of transmitter
'
B
' as follows:
NOTE
Transmitter B's RF output is routed through a relay in
transmitter 'A'. If desired, the routing can be changed
by installing an appropriate RF coaxial cable
between transmitter B's RF output connector and the
system's RF output connector.
(a)
Turn off or verify transmitter '
A
' has been turned
off. Set its
POWER
switch to
OFF
.
(b) Perform a complete functional test of transmitter
'
B
', including remote control operation, as
detailed in the ND500II technical instruction
manual.
(c)
On completion of tests, set the transmitter's
MOD
and
KEYING
switches to
ON
. Ensure the carrier
level and modulation depth are set to the
intended levels.
6.5
COMPLETION OF STAND ALONE
TESTS:
On completion of stand alone transmitter
tests, restore all the system to its normal configuration
as follows:
(a) Turn off or verify both transmitters are turned
off. Set their
POWER
switch to
OFF
.
(b) Verify the RF coaxial cable is installed between
2A7J2 and 1A7J3.
6.6 MAIN/STANDBY
CHECKS:
Check the
main/standby operation of the '
A
' and '
B
' transmitters
as follows:
(a) Verify requirements of paragraphs 6.1 through
6.5 have been completed and are being met.
(b) Verify a suitable 50 ohm load is connected to
the system's RF output connector.
(c) Ensure transmitter remote controls will not
affect testing by setting the
CONTROL
switch of
the '
A
' and '
B
' transmitters to
LOCAL
.
(d) Set
or
verify
MONITOR
switch of the '
A
'and '
B
'
transmitters is set to
NORMAL
.
